/* ==========================================================================
   Animations & Transitions
   ========================================================================== */

/* Keyframe Animations
   ========================================================================== */

@keyframes fadeIn {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadeInDown {
  from {
    opacity: 0;
    transform: translateY(-30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes slideInLeft {
  from {
    opacity: 0;
    transform: translateX(-50px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes slideInRight {
  from {
    opacity: 0;
    transform: translateX(50px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes scaleIn {
  from {
    opacity: 0;
    transform: scale(0.9);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

@keyframes bounce {
  0%, 20%, 50%, 80%, 100% {
    transform: translateY(0);
  }
  40% {
    transform: translateY(-10px);
  }
  60% {
    transform: translateY(-5px);
  }
}

@keyframes pulse {
  0% {
    transform: scale(1);
  }
  50% {
    transform: scale(1.05);
  }
  100% {
    transform: scale(1);
  }
}

@keyframes shimmer {
  0% {
    background-position: -1000px 0;
  }
  100% {
    background-position: 1000px 0;
  }
}

/* Animation Classes
   ========================================================================== */

.animate-fade-in {
  animation: fadeIn 0.6s ease-out;
}

.animate-fade-in-up {
  animation: fadeInUp 0.8s ease-out;
}

.animate-fade-in-down {
  animation: fadeInDown 0.8s ease-out;
}

.animate-slide-in-left {
  animation: slideInLeft 0.8s ease-out;
}

.animate-slide-in-right {
  animation: slideInRight 0.8s ease-out;
}

.animate-scale-in {
  animation: scaleIn 0.5s ease-out;
}

.animate-bounce {
  animation: bounce 2s infinite;
}

.animate-pulse {
  animation: pulse 2s infinite;
}

/* Delay Classes */
.delay-100 {
  animation-delay: 100ms;
}

.delay-200 {
  animation-delay: 200ms;
}

.delay-300 {
  animation-delay: 300ms;
}

.delay-400 {
  animation-delay: 400ms;
}

.delay-500 {
  animation-delay: 500ms;
}

/* Scroll Reveal Animations
   ========================================================================== */

.reveal {
  opacity: 0;
  transform: translateY(40px);
  transition: opacity 0.7s cubic-bezier(0.4, 0, 0.2, 1),
              transform 0.8s cubic-bezier(0.4, 0, 0.2, 1);
  will-change: opacity, transform;
}

.reveal.active {
  opacity: 1;
  transform: translateY(0);
}

/* Image Hover Effects
   ========================================================================== */

.image-hover-zoom {
  overflow: hidden;
  position: relative;
}

.image-hover-zoom img {
  transition: transform 0.6s ease;
}

.image-hover-zoom:hover img {
  transform: scale(1.1);
}

.image-hover-overlay {
  position: relative;
  overflow: hidden;
}

.image-hover-overlay::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(0, 0, 0, 0);
  transition: background-color var(--transition-base);
}

.image-hover-overlay:hover::after {
  background-color: rgba(0, 0, 0, 0.3);
}

/* Loading States
   ========================================================================== */

.loading-skeleton {
  background: linear-gradient(
    90deg,
    var(--color-gray-100) 0%,
    var(--color-gray-200) 50%,
    var(--color-gray-100) 100%
  );
  background-size: 1000px 100%;
  animation: shimmer 2s infinite;
}

.spinner {
  border: 3px solid var(--color-gray-200);
  border-top: 3px solid var(--color-black);
  border-radius: 50%;
  width: 40px;
  height: 40px;
  animation: spin 1s linear infinite;
}

@keyframes spin {
  0% {
    transform: rotate(0deg);
  }
  100% {
    transform: rotate(360deg);
  }
}

/* Page Transition
   ========================================================================== */

.page-transition {
  opacity: 0;
  animation: fadeIn 0.5s ease-out forwards;
}

/* Smooth Image Loading
   ========================================================================== */

/* Base image styles for lazy loading */
img[data-src] {
  opacity: 0;
  transform: scale(0.95);
  transition: opacity 0.5s cubic-bezier(0.4, 0, 0.2, 1),
              transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

img[data-src].loading {
  opacity: 0;
  transform: scale(0.95);
}

img.loaded {
  opacity: 1;
  transform: scale(1);
}

/* Loading placeholder for images */
img[data-src]:not(.loaded):not(.error) {
  background: linear-gradient(
    90deg,
    #f0f0f0 0%,
    #f8f8f8 50%,
    #f0f0f0 100%
  );
  background-size: 200% 100%;
  animation: shimmer 1.5s ease-in-out infinite;
  min-height: 200px; /* Prevent layout shift */
}

/* Error state */
img.error {
  opacity: 0.5;
  background: #f5f5f5;
}

/* Hover Lift Effect */
.hover-lift {
  transition: transform var(--transition-base), box-shadow var(--transition-base);
}

.hover-lift:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
}

/* Underline Animation */
.underline-animate {
  position: relative;
  display: inline-block;
}

.underline-animate::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 2px;
  background-color: var(--color-accent);
  transition: width var(--transition-base);
}

.underline-animate:hover::after {
  width: 100%;
}

/* Performance Optimizations
   ========================================================================== */

/* Enable hardware acceleration for animations */
.reveal,
.portfolio-item,
.portfolio-image,
img[data-src],
.study-item {
  -webkit-backface-visibility: hidden;
  backface-visibility: hidden;
  -webkit-perspective: 1000;
  perspective: 1000;
  transform: translateZ(0);
}

/* Improve scrolling performance */
.portfolio-grid,
.studies-grid,
.year-section {
  contain: layout style paint;
}

/* Respect user preferences */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }

  .reveal {
    opacity: 1;
    transform: none;
  }

  img[data-src] {
    opacity: 1;
    transform: none;
  }
}